user number problems

Here is what I am doing, I am working on a script to allow uses to sign up for a website. I am using mysql as the database. Each user has a unique user number.

For the user number field in the database, I have it set at int, auto increment.

The problem I have found though is that it always goes up... even if someone leaves.

Let me explain differently. If I have 6 people sign up, and then number 4 leaves, the next person to join the site becomes number 7, the number 4 slot stays empty.

How do I make it so that it will automatically fill in empty spots instead of just always going up. Thanks

See this thread: http://codewalkers.com/archives/sqlhelp/281.html